UK to US visa posiblities to travel [closed]

Your girlfriend would not be able to obtain a visa because of your visa status, as explained on the US Embassy & Consulates in the UK web site:

U.S. visa law does not recognize common-law relationships; therefore a partner or fiancée is not eligible to apply for derivative visa status. In such cases, the partner is required to qualify for a visa in his or her own right. Partners who are members of the household of the principal visa holder and whose primary purpose in traveling to the United States is to accompany that person, may apply for a B-2 visa. Partners who intend working or studying require the appropriate work or student visa.

U.S. immigration at the port of entry determines how long a person may remain in the United States. The holder of a B-2 visa may be admitted for an initial period of six months, which is extendable in six month increments. Those wishing to remain longer than six months will be required to apply for an extension of stay with the US Citizenship and Immigration Services having jurisdiction over their place of residence in the United States.

Don't be mislead or discouraged by anecdotal reports. A strong and forthright B visa application has a considerable chance of being granted. Last year's statistics indicate that 80 percent of Great Britain and Northern Ireland applicants were successful.

If you have an L1-B, your partner can apply for an L2 which gives her the right to work. It is preferred you be married to do so because it is easier but you could attempt being partners.

I have done the process myself. We got married and both my wife and I now work in the US.